Answer:d.Paleozoic Era
Explanation:
Paleozoic Era is hallmarked by climate, animals & plants.
This Era includes the Ordovician Period, Silurian Period and the Devonian Period.
The Silurian Period is one during this era where aquatic plants and animals evolved.
The last Caribbean monk seal that died was the last member of a SPECIE.
All the living things, both plants and animals are placed in a hierarchical order depend on their characteristics and specie is the least stage on that rank. A specie refers to a specific group of animals which share similar physical characteristics. The Caribbean monk seal for instance is one of the specie of fishes that exist on earth.Thus, a specie is a basic unit of classification which recognize animals of the same sort.<span />
14C (carbon-14) can be used to date a 20,000 year old skeleton
D.
If the vibrations have a low frequency, the sound is heard as a __low-pitched sound_____. If the vibrations have a high frequency, then the sound is heard as a __high-pitched sound_____.
Explanation:
High pitched sound is of higher frequency because they make the air molecules vibrate much faster than low-pitched sound. Due to their high frequency, their wavelength is shorter (Remember wavelength and frequency are inversely proportional). Vice versa is true to the low-pitched sound. They vibrate air molecules slower than high-pitched sound. Their wavelength is longer and frequency smaller.
Learn More:
For mor on pitch of sound check out;
brainly.com/question/61859
brainly.com/question/1509263
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